1. Field of the Invention
The present invention relates to an engraving dial formed of an upper dial plate and a lower dial plate for use in an inside ring engraving machine and, more particularly to such an engraving dial, which has the top and bottom sides of each dial plate respectively engraved with a respective set of signs for engraving selection.
2. Description of the Related Art
A ring is a circular band of precious metal, worn as an ornament. For memorial purpose, people may have the inside ring engraved with letters, numbers, symbols, etc., (hereinafter called signs).
A machine for engraving signs on the inside ring of a ring is called xe2x80x9cinside ring engraving machinexe2x80x9d. An inside ring engraving machine is used with an engraving dial to achieve the engraving. The invention pertains to an engraving dial for inside ring engraving machine.
FIGS. 1 and 2 show an engraving dial constructed according to the prior art. According to this design, the engraving dial, referenced by 70, comprises a lower dial plate 71, a hub 72 locked to the lower dial plate 71 at the top, and an upper dial plate 73 rotatably mounted on the hub 72 and supported on the top side of the lower dial plate 71. The dial plates 71 and 73 have engraved signs 74 or 75 at the top. The lower dial plate 71 has V-notches 76 equiangularly spaced around the periphery.
When engraving words, for example, xe2x80x9cMyxe2x80x9d on the inside ring and assuming that the initial xe2x80x9cMxe2x80x9d is at the lower dial plate 71 and the last letter xe2x80x9cyxe2x80x9d is at the upper dial plate 73, thus the engraving operation is as follows:
At first, as shown in FIG. 3, the engraving dial 70 is installed in the base 61 of the inside ring engraving machine 6, and then the engraving dial 70 is rotated to let the stopper 62 engage the V-notch 76 corresponding to the sign xe2x80x9cMxe2x80x9d, holding the lower dial plate 73 in the engraving position. Thereafter, fasten up the tightening knob 63 to lock the engraving dial 70 to the base 61 of the inside ring engraving machine 6. Thus the user can operate the inside ring engraving machine to move the tracing stylus shaft 64 on the letter xe2x80x9cMxe2x80x9d, causing the diamond engraving cutter (not shown) to engrave the inside ring of the loaded ring.
When engraving the letter xe2x80x9cyxe2x80x9d, as shown in FIG. 4, rotate the upper dial plate 73, for enabling the steel balls 79 of the locators 78 to be respectively forced by the respective compression springs 80 into the recessed round holes 81 at the lower dial plate 71 (See FIG. 2). Upon engagement of the steel balls 79 into the recessed round holes 81 of the lower dial plate 71, a positioning click sound is produced, and the upper dial plate 73 is locked to the lower dial plate 71. At this time, the signs 75 at the upper dial plate 71 and the signs 74 at the lower dial plate 71 are respectively aligned. Thereafter, fasten up the hold down bolt 82 to lock the upper dial plate 73 to the lower dial plate 71, and then rotate the engraving dial 70 to let the stopper 62 engage the V-notch corresponding to the sign xe2x80x9cyxe2x80x9d at the upper dial plate 73, and then fasten up the tightening knob 63 to lock the engraving dial 70 to the base 61 of the inside ring engraving machine 6. Thus, the user can then engrave the sign xe2x80x9cyxe2x80x9d on the inside ring of the loaded ring.
This design of engraving dial provides only one combination of signs, for example, the combination of full cap signs at the lower dial plate and minuscule signs at the upper dial plate. Further, because one dial plate provides only one form of signs, the user may have to prepare additional dial plates of different forms of signs for selection.
The present invention has been accomplished under the circumstances in view.
It is the main object of the present invention to provide an engraving dial, which has the top and bottom sides of each dial plate respectively engraved with a respective set of signs, providing four combinations for engraving selection.
To achieve this and other objects of the present invention, the engraving dial comprises a bottom holder plate, the bottom holder plate comprising an upper part, a lower part, the lower part of the bottom holder plate having an outer greater than the upper part of the bottom holder plate, a center through hole through the lower part and upper part of the bottom holder plate, and a plurality of screw holes extended through the lower part of the bottom holder plate and equiangularly spaced around the center through hole of the bottom holder plate; a lower dial plate, the lower dial plate comprising a center through hole adapted to accommodate the lower part of the bottom holder plate, a plurality of peripheral notches equiangularly spaced around the periphery thereof, two sets of signs respectively engraved on top and bottom sides thereof at imaginary radial lines between the center through hole of the lower dial plate and the peripheral notches, a plurality of recessed round holes symmetrically formed at the top and bottom sides and equiangularly spaced around the center through hole of the lower dial plate at an imaginary circle concentric to the center through hole of the lower dial plate; an upper dial plate, the upper dial plate comprising a center through hole, a peripheral opening, two sets of signs respectively engraved on top and bottom sides thereof corresponding to the signs at the lower dial plate; a top holder plate, the top holder plate comprising an upper part, a lower part fitted into the center through hole of the upper dial plate, the lower part of the top holder plate having a diameter smaller than the upper part of the top holder plate, a center through hole adapted to accommodate the upper part of the bottom holder plate, and a plurality of countersunk holes respectively fastened to the screw holes of the bottom holder plate by screws; and at least one locator, the at least one locator each comprising a retaining member respectively fastened to and vertically extended through the top holder plate, the retaining member having a bottom mounting hole, a compression spring mounted in the bottom mounting hole of the retaining member, and a steel ball supported on the compression spring at a bottom side and forced by the compression spring to selectively engage the recessed round holes of the lower dial plate.